diff --git a/linux/uart/UartComIF.cpp b/linux/uart/UartComIF.cpp
index eb12dee..c84affa 100644
--- a/linux/uart/UartComIF.cpp
+++ b/linux/uart/UartComIF.cpp
@@ -79,6 +79,7 @@ int UartComIF::configureUartPort(UartCookie* uartCookie) {
     setStopBitOptions(&options, uartCookie);
     setDatasizeOptions(&options, uartCookie);
     setFixedOptions(&options);
+    setUartMode(&options, *uartCookie);
     if(uartCookie->getInputShouldBeFlushed()) {
         tcflush(fd, TCIFLUSH);
     }
@@ -403,13 +404,13 @@ ReturnValue_t UartComIF::handleNoncanonicalRead(UartCookie &uartCookie, UartDevi
         return RETURN_FAILED;
     }
     else if (bytesRead != static_cast<int>(requestLen)) {
-        sif::debug << "UartComIF::requestReceiveMessage: Only read " << bytesRead <<
-                " of " << requestLen << " bytes" << std::endl;
-        return RETURN_FAILED;
-    }
-    else {
-        iter->second.replyLen = bytesRead;
+        if(uartCookie.isReplySizeFixed()) {
+            sif::warning << "UartComIF::requestReceiveMessage: Only read " << bytesRead <<
+                    " of " << requestLen << " bytes" << std::endl;
+            return RETURN_FAILED;
+        }
     }
+    iter->second.replyLen = bytesRead;
     return HasReturnvaluesIF::RETURN_OK;
 }
 
diff --git a/linux/uart/UartCookie.cpp b/linux/uart/UartCookie.cpp
index bfd815e..2e9cede 100644
--- a/linux/uart/UartCookie.cpp
+++ b/linux/uart/UartCookie.cpp
@@ -87,3 +87,11 @@ bool UartCookie::getInputShouldBeFlushed() {
 object_id_t UartCookie::getHandlerId() const {
     return this->handlerId;
 }
+
+void UartCookie::setNoFixedSizeReply() {
+    replySizeFixed = false;
+}
+
+bool UartCookie::isReplySizeFixed() {
+    return replySizeFixed;
+}
diff --git a/linux/uart/UartCookie.h b/linux/uart/UartCookie.h
index 69f59a5..faf95d5 100644
--- a/linux/uart/UartCookie.h
+++ b/linux/uart/UartCookie.h
@@ -95,6 +95,14 @@ public:
     void setTwoStopBits();
     void setOneStopBit();
 
+    /**
+     * Calling this function prevents the UartComIF to return failed if not all requested bytes
+     * could be read. This is required by a device handler when the size of a reply is not known.
+     */
+    void setNoFixedSizeReply();
+
+    bool isReplySizeFixed();
+
 private:
 
     const object_id_t handlerId;
@@ -107,6 +115,7 @@ private:
     uint8_t bitsPerWord = 8;
     uint8_t readCycles = 1;
     StopBits stopBits = StopBits::ONE_STOP_BIT;
+    bool replySizeFixed = true;
 };
 
 #endif